Proportional navigation system for
a spinning body in free space



y 1970 w. a. M LEAN Re. 26,887

PROPORTIONAL NAVIGATION SYSTEM FOR A SPINNING BODY IN FREE SPACEOriginal Filed June 8. 1959 5 Sheets-Sheet l /SOI..ENOID o snnsn VALVEAND FUEL COMBUSTION mesa DIRECTION OF SPIN PRIMARY MIRROR OXIDIZER LINEFUEL LINE /LATRAL JET SECONDARY MIRRO DIRECTION OF SPIN FIG. 2.

INVENTOR. WILLIAM B. MCLEAN BY MUTATION DAMPER bmw AT RNEYS.

May 19, 1970 w. B. M LEAN 26,887

PROPORTIONAL NAVIGATION SYSTEM FOR A SPINNING BODY IN FREE SPACE OnginalFiled June 8, 1959 5 Sheets-Sheet PRIMARY MIRROR onscrom 2s smmTELESCOPE AXIS AXIS U 22 I b TARGET SECONDARY manor! m wm {I RADIATIONFROM TARGET FOCAL PLANE Q D Q O G DGG l I 0 DETECTOR cunnsu'r CIRCUITCURRENT F INVENTOR.

WILLIAM B. MC LEAN y 19, 1970 w. B. M LEAN Re. 26,887

PROPORTIONAL NAVIGATION SYSTEM FOR A SPINNING BODY IN FREE SPACEOriginal Filed June 8, 1959 5 Shuts-Shae f s z Ill ul- 3 \Q" o 2:: F

Dz I 3 1 9 N L9 I" INVENTOR. WILLIAM 8. MC LEAN 2', BY

y 1970 w. B. M LEAN Re. 26,887

PROPORTIONAL NAVIGATION SYSTEM FOR A SPINNING BODY IN FREE SPACE OmgmalFiled June 8, 1959 5 Sheets-Shnei DETECTOR cam.

FIG. 8.

SOLENOID SIGNAL AMPLIFIER OXIOIZER FUEL INJECTOR VALVE FUEL LATERAL JET27 couausnon cnmaea PRECESSING JET TARGET PRECESSING JET REACTION FORCECENTER OF GRAVITY PRECESSING JET TARGET IMAGE FIG. IO.

DIRECTION OF SPIN INVENTOR. WILLIAM B. MC LEAN BY May 19, 1970 w. a. MLEAN Re. 26,887 PROPORTIONAL NAVIGATION SYSTEM FOR A SPINNING BODY INFREE SPACE Ongmal Filed June 8, 1959 5 Sheets-Sheet 5 IMAGE POSITIONSSIGNAL MAGNITUDE OIIIIIIIIIIIIWIII FIG. l3. FIG. l5.

FIG. I4.

WILLIAM B. MC LEAN INVENTOR.

MAM

AT RNEYS.

United States Patent Oflice Re. 26,887 Reissued May 19, 1970 26,887PROPORTIONAL NAVIGATION SYSTEM FOR A SPINNING BODY IN FREE SPACE WilliamB. McLean, China Lake, Calif., assignor to Walter G. Finch, Baltimore,Md.

Original No. 3,216,674, dated Nov. 9, 1965, Ser. No. 818,979, June 8,1959. Application for reissue May 15, 1967, Ser. No. 646,745

Int. Cl. B64g 1/20 U.S. Cl. 2443.16 48 Claims Matter enclosed in heavybrackets appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE The direction of a radiation source isdetected to provide signals to control jet motors, one of which isoriented to produce a precessing torque on a spinning vehicle; onotherof which is oriented to provide an acceleration lateral to the spinaxis. The motors operate intermittently in synchronism with the spin ofthe vehicle. A nutation damper damps out nutational movement.

The invention herein described may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

The present invention relates to space vehicles and more particularly toan orientation and velocity control [automatic and self-containednavigation] system for a space vehicle spinning about its central axisas it travels in space.

The present device utilizes the properties of a spinning body in freespace for orientation and velocity control [proportional navigation]thereof. A body spinning in free space has [all the] properties of agyroscope, and therefore, by imparting a spin to a space vehicleassembly it can be made to perform like a gyroscope while traveling infree space. To achieve stable spin about a fixed geometrical axis in thebody a nutation damper is employed [required]. By including, in thespace vehicle assembly, a [tracking] system for detectingelectromagnetic radiation [with its optical] [axis coinciding with thespin axis of the vehicle] and a variable thrust jet motor on the outerperiphery of the spinning vehicle, the vehicle can be made to precess soas to [always] point its spin axis in a predetermined direction [at atarget body that is emitting electromagnetic] [radiation]. To provide [acollision course between] velocity control of the spinning vehicle[assembly and] [the target body] a second jet motor for producinglateral acceleration is provided whose thrust axis passes through thecenter of gravity of the spinning vehicle [and is 90 around theperiphery of the] [vehicle from the precessing jet motor]. Bycontrolling both jet motors with a single valve so that the pressurebehind each jet is varied proportional to the detected [target] signalthe vehicle can be made to travel a course which will result in acollision with a [the] target body. This device can be made to operatein any environment, including the earths atmosphere, in which the motionof the vehicle or body is controlled primarily by the jet motors. Toachieve this condition, aerodynamic forces must be reduced to a minimum.

It is an object of the invention therefore to provide [a] an orientationand velocity control [self-] [contained navigation] system for a vehicletraveling in space or in any environment where the relative motion ofthe vehicle is controlled primarily by the propulsion means containedtherein.

It is another object of the invention to provide a new and usefulvehicle for space travel having an orientation and velocity control [aself-contained guidance] system therein which will automatically followa collision course with a target body emitting electromagneticradiations.

Still another object of the invention is to provide a vehicle [device]which utilizes the properties of a spinning body in free space fororientation and velocity control [proportional navigation] thereof.

A further object of the invention is to provide a vehicle which whenhaving a spin imparted thereto will perform like a gyroscope whiletraveling in free space, and which contains tracking and propulsionmeans for following a collision course with a chosen target body that isemitting electromagnetic radiation.

A still further object of the invention is to provide a proportionalnavigation system for a space vehicle where the propulsion system iscontrolled by a target signal from a seeker contained in the vehicle.

Other objects and many of the attendant advantages of this inventionwill become readily appreciated as the same becomes better understood byreferences to the following detailed description when considered inconnection with the accompanying drawings wherein:

FIG. 1 is a perspective view of an exemplary [a preferred] embodiment ofthe invention showing the interior of the vehicle;

FIG. 2 is a perspective view of the vehicle of FIG. 1, showing theopposite side thereof;

FIG. 3 is a diagrammatic view showing how radiation from a target isfocused onto the reticle and detector in the vehicle via the primary andsecondary mirrors of the vehicle seeker;

FIG. 4 illustrates the relative position of reticle and target image atthe time of maximum current;

FIG. 5 illustrates an angular position of the reticle relative to thetarget for maximum current;

FIG. 6 shows the relationship and form of detector current and circuitcurrent with reticle and target position;

FIG. 7 is a circuit diagram of a seeker amplifier for amplifying signalsgenerated by the photodetector oell;

FIG. 8 is a diagrammatic illustration of the circuitry and propulsionsystem for an exemplary [a preferred] embodiment of the presentinvention;

FIGS. 9 and 10 are diagrammatic views of the vehicle showing itsdirection of spin and illustrating how the reaction force from theprecessing jet causes the vehicle to precess, as would a gyroscope, toalign its spin axis with the line-of-sight to the target body;

FIG. 11 shows the position of a target image for constant radiationthrough the reticle;

FIG. 12 shows a reticle with alternating clear and opaque sectors on onehalf, and wholly opaque on the other half thereof;

FIG. 13 illustrates the position of a target for maximum current whenusing the reticle of FIG. 12;

FIG. 14 shows target positions for small current using the reticle ofFIG. 12;

FIG. 15 illustrates the signal magnitude as affected by position of thetarget image on the reticle; and

FIG. 16 illustrates a vehicle traveling in space on a collision coursewith a target body.

A body or space vehicle spinning in free space has [all the] propertiesof a gyroscope, and if provided with a nutation damper, such asdisclosed in U.S. Pat. 2,734,- 384, issued Feb. 14, 1956, or in U.S.Pat. application Ser. No. 789,216, filed Jan. 26, 1959 and now U.S. Pat.No. 3,034,745, issued May 15, 1962, for Spin-Axis Stabilized SpaceVehicle Structure, the spinning vehicle will maintain a fixedorientation in space unless acted upon by some external force or forces.Such external forces may be provided by reaction forces produced by jetpropulsion motors carried in the spinning space vehicle,

Referring now to the drawings, like numerals refer to like parts in eachof the figures.

An exemplary embodiment of the [The] present invention [is fornavigating] comprises a space vehicle illustrated in FIGS. 1 and 2,which is presumed to be traveling in space and spinning about itscentral axis, acting like and having all the properties of a gyroscope.The spin of the vehicle is usually imparted thereto at the time it islaunched into space, but jet means can be provided in the vehicle itselffor imparting the spin, if desired. A seeker 12, comprising a telescopiccomparator mounted on the spin axis of the vehicle, detectselectromagnetic (e.g., infrared) radiation from a target, such as themoon, a planet, or some other space vehicle, and generates a signal inaccordance with the position or bearing of the target relative to theoptical axis of the telescope which axis coincides with the spin axis ofthe vehicle. This signal is amplified and converted into an alternatingcurrent signal whose time of occurrence or phase is determined by therelation of the seeker to the target position. In direct response to thesignals from the seeker a small jet motor 16 on the outer periphery ofthe spinning vehicle is caused to operate. By properly orienting thisjet motor with respect to the seeker, as shown in FIGS. 1 and 2, thespinning vehicle 10, since it acts like a gyroscope, will be precessedin space in such a manner as to have its spin axis and thus the opticalaxis of the telescope point directly at a target which is imaged on theseeker 12. In this system the target signal generated by the seeker isnot resolved into any coordinate system; the magnitude of the signalprovides the magnitude of the correction signal. When accurate trackingis achieved the magnitude of the signal is proportional to the angularrate of the line joining the target and the seeker in space.

The optical system of the target seeker comprises a folded reflectingtelescope, having primary and secondary optical mirrors 18 and 19, whoseoptical axis coincides with the spin axis of the vehicle and spins withthe vehicle about those coinciding axes. Mounted on the back of mirror19 is a mutation damper 21 which may be of the type disclosed in theaforementioned Patent 2,734,384 or application Serial No. 789,215 andnow abandoned. Although the nutation damper is shown for convenience asmounted on mirror 19, it is understood, of course, that it could besupported elsewhere; as, for example, on the vehicle body on the otherside thereof. A schematic diagram of the vehicle and seeker is shown inFIG. 3. The optical system, which includes an image chopper or reticle20 mounted at the focal plane of the telescope for rotation therewith,forms radiation from the target into an image and chops it, producing apulsed radiation signal. A photodetector cell 22, such as a lead sulfidedetector, is mounted directly behind the image chopper 20 and convertsthe pulsed radiation signal into an alternating current that can beprocessed by the vehicle's circuitry, hereinafter described.

The chopper action can be understood by considering a simple imagechopper or reticle as shown in FIG. 4. Its surface is divided into twomain sectors of 180. When the telescope forms the image of the targe onthe wholly clear portion of the reticle, the radiation passes throughthe reticle and impinges on the detector. When the image falls on theopaque portions 17 of the reticle the radiation is interrupted, and thedetector receives no energy.

The current from the detector is related to the rotational position ofthe reticle. Whenever the target image is wholly in the clear portion 15of the reticle, the circuit current is at maximum. For instance, if thetarget is to the right of the telescope, the current will be at maximumwhen the clear part 15 of the reticle is on the left side of the axis,as in FIG. 4. The direction of the target relative to the telescope axisdetermines the time of occurrence or phase of the maximum current, as inFIG. 5

for instance. Because the electronic circuitry used rounds-off thepulses, the current from the seeker amplifier 14 appears as anundulating line, as shown in FIG. 6. The signal from the detector 22 isamplified by the circuit of FIG. 7, and, still containing both phase andamplitude information, is fed back to the solenoid coil 24 of a solenoidoperated valve 26, as shown in FIG. 8, which operates the precessing jetmotor 16. Thus the signal produces an alternating field in the solenoid24 with just the frequency at which the vehicle 10 is spinning.

With the reticle 20 mounted on vehicle 10 the signal frequency isidentical with the spin rate of the vehicle. Therefore, the current isautomatically and exactly synchronized with the vehicle spin.

The alternating field, synchronized with the vehicle spin acts on thesolenoid operated valve 26 and thus the precessing jet 16 and results ina torque on the spinning vehicle proportional to the current in thesolenoid coil 24. The spinning vehicle assembly 10, acting like agyroscope, precesses in response to this alternating field.

Consider the forces on the spinning vehicle. Viewing vehicle 10 of FIGS.9 and 10 from beyond the target, the vehicle is seen as spinning in aclockwise direction with the target to the left of the spin axis 26 andthe target image appearing to the right (FIG. 10). Radiation passingthrough the clear portion 15 will produce a current which energizessolenoid 24 and activates precessing jet 16. The reaction force from theprecessing jet 16, shown as a heavy arrow in FIG. 9 exerts a torque onthe vehicle which is felt as a precessing force around in the directionof clockwise rotation and effects a turning of the vehicle so that thespin axis 26 points directly at the target and the target image iscentered on the reticle 20.

The spinning vehicle, acting like a gyroscope rotating about spin axis26, thus transforms the torque, produced by the precessing jet 16, aboutan axis that goes through the center of gravity and normal to the paperinto a precession or rotation of spin axis 26 about axis 28 which isperpendicular to and intersects the thrust axis of the precessing jet 16and intersects the center of gravity of the vehicle 10, as shown inFIGS. 9 and 10. That is, with gyro rotation about a first axis, a torqueapplied about a second axis will cause the gyro to precess about a thirdaxis, all of the axes being normal to each other. As the current in thesolenoid 24 passes through a maximum, operating the valve 26 and thusthe precessing jet 16, the torque produced by the thrust of theprecessing jet precessing the vehicle and telescope, is maximum. It isonly necessary, then, that the reticle 20 have the correct position withrespect to the precessing jet 16 for this maximum current to occur atjust the right time to produce a torque in the direction of the target.

Because the current is maximum when the target image is in the center ofthe clear segment 15 of reticle 20, the torque on the vehicle andtelescope is in the direction of the target; see FIG. 10. The vehicleacting like a gyroscope responds to this torque by precessing its spinvector (i.e., axis) toward the target. With the telescope axis along thespin vector, the telescope thus rotates toward the target. In thismanner the gyro-like spinning vehicle assembly 10 keeps the telescopepointed at the target body.

If the seeker telescope is pointing directly at the target 30, FIG. 11,a constant amount of radiation passes through the reticle 20 at alltimes; the detector generates no pulsating current; no current flows inthe solenoid coil; and the vehicle experiences no precessing torque. Thetelescope remains pointed in this fixed direction in space, looking atthe target, until a change in the bearing angle (line-of-sight to thetarget) causes the target, image 30 to move away from the center of thereticle.

As described, the seeker 12 would receive a full tracking signal as soonas the image barely moved otf the center of the reticle 20. However, thepreferred reticle has alternating clear and opaque sectors, as shown inFIG. 12. This pattern gives the chopping frequency a more convenientvalue for electronic amplification and reduces background clutter frombackground radiation. In addition, it makes the tracking signalproportional to the bearing rate.

The target image formed on the reticle is not infinitely small. Whenthis target image, in FIG. 13. moves well away from the center of thereticle, the widening pieshaped sectors alternately completely block theradiation, then permit it all to pass. The pulsating current is then atmaximum. FIG. 13 also shows target position for maximum current.

If the image nears the center of the reticle, the narrow ends of thepie-shaped sections only partially obscure and partially transmit theimage radiation as shown in FIG. 14. The magnitude of the amplifiedcurrent, as a function of target image position, appears as in FIG. 15.The vehicle will receive smaller precession torques when the image isonly slightly off the telescopes center than when the target is wellaway from the telescopes axis, as shown by the different positions ofthe target image in FIG. 15.

While the vehicle travels precisely on a course to intercept the targetor reach the target destination, by means of a lateral jet 32hereinafter explained, the telescope will point directly at the targetand no signal will result, because the image will be at the null pointof the chopper 20.

When the direction to the target changes because of changes in target orvehicle velocity, if any, the target image moves away from the reticlecenter and creates a tracking signal. The displacement of the imagegrows until the vehicle's precession rate just equals the sight-linerate of the target. Thus, the seeker telescope mounted on the vehiclereports any changes in the direction of the target that requirealteration of the seeker optical axis (i.e., vehicle spin axis) to haveit coincide with the line-of-sight from the vehicle to the target.Because the telescopes precession rate depends upon the magnitude of thethrust produced by the precessing jet (current in the solenoid of valve26 controls the precessing jet), the pressure difference across the jet(which is proportional to the coil current) becomes a direct measure ofthe bearing rate to the target.

A space vehicle traveling in space on a collision course with anotherbody 30 moving in space is shown in FIG. 16. With the range between thespace vehicle 10 and the other body 30 (e.g., a target planet) closingand the bearing angle remaining constant (i.e., a=fl='y) the vehicle andother body will inevitably collide.

A vehicle of constant speed launched on a collision course with a targetbody in space moving at a constant speed should maintain a constantbearing to the target body to close the range to zero. Thevehicle-to-target bearing must be constant at the end of flight for acollision, and a constant bearing throughout flight will ensue acollision. Since the principles of a collision course are well known inthe art, a further discussion on this point is not considered necessary.

To provide a mechanism of establishing a collision course between thespace vehicle 10 and a target 30 moving in space, the spinning vehiclemust be provided with a lateral acceleration which is in the planedetermined by the sequential positions of the sight line from vehicle totarget and be of a magnitude proportional to the sight line rate. Thiscan be accomplished by providing the vehicle 10 with a second jet (alateral jet) 32 whose thrust axis is through the center of gravity ofthe spinning vehicle, and whose thrust axis is 90 from the thrust axisof the precessing jet as measured around the periphery of the spinningassembly, as shown in FIGS. 1 and 2.

If both the precessing jet 16 and the lateral jet 32 are controlled by asingle valve 26, FIG. 8, in such a way that the pressure behind each jetis varied proportional to the incoming target signal from detector 22,then it can be shown that a direct proportionality exists between thesight line rate and the lateral acceleration of the vehicle in space.This is the necessary and sufiicient condition for a proportionalnavigational course which will result in the collision of the vehicleand target bodies.

Referring again to FIG. 7, this figure shows a wiring diagram of anamplifier which amplifies the target signal generated by thephotodetector cell 22 and feeds it to solenoid coil 24 which operatesvalve 26 and thus the jet motors 16 and 32.

The amplifier circuit, shown by way of example, includes a conventionalpower supply 35 including a transformer 36 having primary and secondarywindings and a fullwave rectifier as shown at 37. Associated with thepower supply 35 is a filtering network 39 of conventional form supplyinga potentiometer 40. Potentiometer 40 supplies power to a phase shifttransformer 42, the primary of which is in the plate circuit of anamplifier tube 44. The photocell 22 is connected in the grid circuit ofan amplifier tube 46 which is a five element tube having screen andsuppressor grids as shown. The input circuit of tube 46 includesphotocell 22 and filter circuits 47 to limit the range of frequencies towhich the system will be sensitive.

The output of tube 46 is connected to the control grid of tube 44 whichcontrols the primary of transformer 42.

The secondary of transformer 42 connects to a conventional phaseshifting circuit network as shown at 50 including a center tappedresistor 51 connected across the secondary and grounded, and a rheostat52. By adjustment of rheostat 52 the phase of the signal pulses beingtransmitted can be adjusted. The phase shifting circuit 50 is connectedto a phase splitting tube 54, the output of which connects to apush-pull power amplifier circuit 56. Circuit network 56 includespush-pulI connected tubes 57 and 58. Numerals 59 and 60 indicate gridresistors.

The power amplifier network 56 is connected to the primary of outputtransformer 68 and the secondary 69 of this transformer is connected tothe solenoid coil 24 which operates valve 26 for the precessing andlateral thrust jets 16 and 32.

By adjusting the variable resistor 52, the phase, or time of occurrence,of the signal pulses from photodetector cell 22 can be adjusted relativeto the angular position of the precessing jet 16 about the spin axis 26of the vehicle so that the direction of precessing is such as to achievestraight line precession of the vehicle in realigning its spin axis 26with the line-of-sight from the seeker to the target as illustrated inFIGS. 9 and 10. Another method of adjusting the phase relative to theangular position of the precessing jet, as previously described, is byphysically orienting the clear and opaque sectors of the reticle aboutthe spin axis with respect to the precessing jet 16.

Referring again to FIG. 8, this figure illustrates how signals generatedby photodetector cell 22, from radiation from a target impingingthereon, are amplified by signal amplifier 14 and caused to operatesolenoid 24 which in turn actuates a. single valve 26. Valve 26 is afuel injector type valve which feeds correct amounts of fuel andoxidizer, for example, into combustion chamber 27. Both the precessingjet 16 and lateral jet 32 are fed at equal gas pressures from combustionchamber 27. The passages from combustion chamber 27 to the jet nozzlesare large in cross-sectional area with respect to the cross-sectionalarea of the jets in order that there will be no pressure drop betweenthe combustion chamber and the jet nozzles.

Though the gas pressure at each of the nozzles are equal to each otherat all times, the cross-sectional areas of the nozzles are of dilferentsizes in order to establish the proportionality of the lateralacceleration and the sight line rate. Less thrust will usually thenecessary to precess the vehicle than will be needed for moving thevehicle on a collision course to eventually collide with a target.

Injector valve 26 is of the type for controlling the quantity ofoxidizer and fuel entering the combustion chamber and of acting to shutoff the propellant flow completely. With this type of valve the thrustof the jets 16 and 32 can be varied according to the amount of oxidizerand fuel allowed to enter the combustion chamber from the oxidizer andfuel tanks, shown in FIG. 1, in response to current passing throughsolenoid 24. Injector valve 26 is similar to that disclosed in US.Patent 2,810,259 issued October 22, 1957.

It has been presumed that the vehicle is traveling at a forward velocityimparted to it when it was launched on its travel in space. Whereadditional forward velocity of the vehicle is desired, to that impartedthereto at the time of launch, the lateral jet may be canted back at anangle to give a forward thrust vector as well as the lateral thrustvector. It must be noted, however, that the thrust axis of this jet mustpass through the center of gravity of the vehicle.

By properly directing a single jet with respect to the center of gravityof the body in order to generate a pulsating torque equivalent to thatof the precessing jet, as previously described, the single jet can beused to achieve the precessing mechanism as well as lateral and forwardthrust. The thrust axis from the single jet must pass close to butdisplaced from the center of gravity of the vehicle by the amountnecessary to produce a torque about the center of gravity equal to thatpreviously produced by the precessing jet.

Obviously, many modifications and variations of the present inventionare possible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. In combinaton, a vehicle having propulsion means therein and capableof traveling in free space while rotating about its central spin axisand having all the prop erties of a gyroscope, and a proportionalnavigation system comprising seeker means mounted on the spin axis ofthe vehicle for detecting electromagnetic radiation from a target bodyand generating electrical signals in response to said radiation, andmeans responsive to the electrical signals generated by said seekermeans for operating said propulsion means in said vehicle in a manner toprecess the vehicle to point its spin axis directly at the target bodyand to move said vehicle along a collision course with said target body.

2. A device as in claim 1 wherein said seeker means includes a foldedreflecting telescope whose optical axis coincides with the spin axis ofthe vehicle, a reticle mounted at the focal plane of said telescope forrotation therewith and for chopping radiation from the target formedinto an image thereon into a pulsed radiation signal, and aphoto-detector cell mounted behind said reticle to convert the pulsedradiation signal into an alternating current.

3. In a vehicle capable of traveling in free space while rotating aboutits central spin axis and having all the properties of a gyroscope, aproportional navigation system comprising seeker means mounted on thespin axis of the vehicle for detecting electromagnetic radiation from atarget body and generating electrical signals in accordance with thebearing of the target relative to the spin axis of the vehicle inresponse to said radiation, means for converting said signals into analternating current the time of occurrence of which is determined by thetarget position, means responsive to the electrical signals generated bysaid seeker means for operating propulsion in said vehicle in a mannerto precess the vehicle to point its spin axis directly at the targetbody and to move said vehicle on a collision course with said targetbody.

4. A vehicle capable of traveling in free space while rotating about itscentral spin axis and having all the properties of a gyroscope,including a proportional navigation system comprising seeker meansmounted on the spin axis of the vehicle for detecting electromagneticradiation from a target body and generating electrical signals inresponse to said radiation which are in accordance with the bearing ofthe target relative to the spin axis of the vehicle, means forconverting said signals into an alternating current the time ofoccurrence of which is determined by the target position, meansresponsive to these converted electrical signals for operatingpropulsion means in said vehicle including a small jet on the outerperiphery of the spinning vehicle in a manner to precess the vehicle topoint its spin axis directly at the target body and a second jet to movesaid vehicle along a collision course with said target body.

5. A device as in claim 4 wherein said second jet has its thrust axispassing through the center of gravity of the vehicle and said second jetis positioned from the precessing jet as measured around the peripheryof the spinning vehicle.

6. A vehicle capable of traveling in free space while rotating about itscentral spin axis and having all the properties of a gyroscope,including a proportional navigation system comprising seeker meansmounted on the spin axis of the vehicle for detecting electromagneticradiation from a target body and generating electrical signals inresponse to said radiation which are in accordance with the bearing ofthe target relative to the spins axis of the vehicle and the time ofoccurrence of which is determined by the position of the target bodythereabout, means responsive to the electrical signals for operatingmeans in said vehicle including a small jet on the outer periphery ofthe spinning vehicle in a manner to precess the vehicle to point itsspin axis directly at the target body and a second jet to move saidvehicle on a collision course with said target body.

7. A device as in claim 6 wherein said second jet has its thrust axispassing through the center of gravity of th vehicle and said second jetis positioned 90 about the periphery of the spinning vehicle as measuredfrom the precessing jet.

8. A device as in claim 6 wherein the cross-sectional areas of thenozzles of said jets are of different sizes such as to establish theproportionality between the vehicles acceleration along a collisioncourse and the precession rate of pointing the vehicles spin axisdirectly at the target body.

9. A device as in claim 6 wherein said small jet has a thrust axis whichis parallel to the spin axis of the vehicle.

10. A device as in claim 9 wherein the torque produced by thrust fromthe precessing jet is transformed into a precession of the vehicles spinaxis in a direction perpendicular to both the spin axis and the axisintersecting the center of gravity of the vehicle perpendicular to thethrust axis of the precessing jet.

11. A device as in claim 6 wherein said means responsive to saidelectrical signals for operating the propulsion means comprises asolenoid operated valve for feeding fuel to a combustion chamber inamounts proportional to and in phase with said electrical signals.

12. A device as in claim 11 wherein said combustion chamber has passagesconnected therewith to said precessing jet and said second jet forsupplying gases of combustion to said jets at equal pressures.

13. A device as in claim 11 wherein said solenoid operated valve isoperable to vary the thrust from both said propulsion jets in proportionto said electrical signals.

14. A device as in claim 6 wherein nutation damper means is includedtherein for stabilization of the vehicles spin axis.

15. In combination, a [A] gyroscopic spinning body having an axis ofspin for use in detecting an energy emitting source, [said spinning bodyhaving an axis of spin,] means on said body responsive to energy emittedfrom said source and providing an output signal representing the radialdirection of said source with respect to said axis of spin, andprecessing means within said body responsive to said output signal forcausing said spin axis to approach alignment with said energy emittingsource.

16. In combination, a [A] gyroscopic spinning body I having an axis ofspin and adapted for tracking an energy emitting source, [said spinningbody having an axis of] [spin,] means carried by said spinning bodyresponsive to energy emitted from said energy emitting source forgenerating an output signal, and [carried by said spinning body,] meanswithin said body responsive to said output signal [first mentionedmeans] for applying a processin force to said spinning body [andcausing] to cause said spin axis to approach alignment with said energyemitting source.

17. The device of claim 16 wherein said force is an intermittent forceapplied at a frequency equal to the spin frequency of said spinningbody.

18. In combination, a [A] spinning body having an axis of spin andhaving all the properties of a gyroscope and adapted for tracking anenergy emitting source, [said spinning body acting as a gyro and having][an axis of spin] means carried by said spinning body responsive toenergy emitted from said energy emitting source [carried by saidspinning body, said means] for providing an output signal having afrequency equal to the spin frequency of said spinning body, andprecessing means within said body, responsive to said [the] outputsignal of said [first mentioned] responsive means for applying anintermittent force to said spinning body to cause [which intermittentforce causes] said spin axis to approach alignment with said energyemitting source.

19. The combination as recited in [device oi] claim 18 [havingadditional], and additionally means responsive to said [the] outputsignal [of said first mentioned] [means] for applying an additionalintermittent force to said spinning body to cause [which additionalintermittent force causes] motion of said spinning body transverse tosaid axis of spin.

20. A vehicle capable of traveling in free space and adapted to be spinstabilized about a spin axis, said vehicle including:

means for generating a signal having a frequency pro-' portional to thespin frequency of said vehicle; means on said vehicle for applyingtorque to said vehicle; and

means resp nsive to said signal and coupled to said torque applyingmeans for causing said vehicle to precess so as to reorient said spinaxis in a predetermined direction.

21. In combination, a vehicle capable of traveling in free space andadapted to be spin stabilized about a spin axis,

means in said vehicle for generating a signal having a frequencyproportional to the spin frequency of said vehicle;

means on said vehicle for applying a force to said vehicle having anacceleration component transverse to said axis of spin;

means responsive to said signal and coupled to said force applying meansfor causing said vehicle to precess and change its velocity;

and nutation damper means carried by said vehicle for damping nutationalmovement.

22. In a vehicle capable of traveling in free space while rotating abouta spin axis, an orientation control system comprising:

means carried by said vehicle for generating a signal having a frequencyproportional to the spin frequency of said vehicle;

jet means on said vehicle having a thrust axis displaced from the centerof gravity of said vehicle; on

means responsive to said signal and coupled to said jet means foroperating said jet means for applying a torque to said vehicle forcausing said vehicle to precess so as to move said spin axis to point ina predetermined direction.

23. In a vehicle capable of traveling in free space and adapted to bespin stabilized about a spin axis, a velocity control system comprising:

means carried by said vehicle for generating a signal having a frequencyproportional to the spin frequency of said vehicle;

jet means on said vehicle having a thrust component substantiallythrough the center of gravity of said vehicle; and

means responsive to said signal and coupled to said jet means foroperating said jet means to apply a force to said vehicle to cause saidvehicle to precess, with said force having an acceleration componenttransverse to said axis.

24. In a vehicle capable of traveling in free space while rotating abouta spin axis, orientation control apparatus comprising:

jet means on said vehicle having a thrust axis displaced from said spinaxis and having a thrust component substantially paralleling said spinaxis; and

means coupled to said jet means for operating said jet means forapplying a torque to said vehicle for causing said vehicle to precess soas to move said spin axis to a predetermined orientation.

25. In a vehicle capable of traveling in free space and capable of beingspin stabilized about a spin axis, velocity control apparatuscomprising:

jet means on said vehicle having a thrust component acting substantiallythrough the center of gravity of said vehicle; and

means coupled to said jet means for operating said jet means to apply aforce to said vehicle to cause said vehicle to precess, with said forcehaving an acceleration component transverse to said axis of spin.

26. In a vehicle capable of traveling in free space and adapted to bespin stabilized about a spin axis, an Orientation control systemcomprising:

detector means carried by said vehicle and adapted to directionallydetect an object in space and for gen-- erating a signal in responsethereto; means carried bydsaid vehicle for applying a torque to saidvehicle; on

means responsive to said signal and coupled to said torque applyingmeans for causing said vehicle to precess so as to orient said spin axiswith respect to said object.

27. An orientation control system comprising:

a spin stabilized vehicle; means carried by said vehicle and responsiveto energy emitted from an energy emitting source for generating asignal;

means carried by said vehicle; for applying a torque to said vehicle;and

means responsive to said signal and coupled to said torque applyingmeans for causing said vehicle to precess so as to orient its spin axiswith respect to said energy emitting source.

28. In a vehicle capable of traveling in free space while rotating abouta spin axis, an orientation control system comprising:

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal;

means carried by said vehicle for applying a torque to said vehicle; and

means responsive to said signal and coupled to said torque applyingmeans for causing said vehicle to process so as to orient said spin axiswith respect to said energy emitting source.

29. In a vehicle capable of traveling in free space and adapted to bespin stabilized about a spin axis, a veloct'ty control systemcomprising:

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal;

means responsive to said signal for applying a force to said vehicle tocause said vehicle to precess and accelerate said vehicle substantiallytransverse to said axis;

and nutation damper means carried by said vehicle for damping nutationalmovement.

30. In a vehicle capable of traveling in free space while rotating abouta spin axis, an orientation and velocity control system comprising:

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal; and

means responsive to said signal for applying a torque to mid vehicle forprecessing said vehicle to point its spin axis to a predetermined anglewith respect to said source and for applying a force to said vehicle forcausing acceleration of said vehicle substantially transverse to saidaxis.

31. In a vehicle capable of traveling in free space while rotating abouta spin axis, an orientation control system comprising.

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal;

means on said vehicle for applying torque to said vehicle; and

means responsive to said signal and coupled to said torque applyingmeans for causing said vehicle to precess so as to reorient said spinaxis in a predetermined direction with respect to said source.

32. In a vehicle capable of traveling in free space while rotating abouta spin axis, an orientation control system comprising:

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal;

jet means on said vehicle having a thrust axis displaced from said spinaxis and having a thrust component substantially paralleling said spinaxis; and

means responsive to said signal and coupled to said jet means foroperating said jet means for applying a torque to said vehicle forcausing said vehicle to precess so as to reorient said spin axis withrespect to said energy emitting source.

33. In a vehicle capable of traveling in free space and adapted to bespin stabilized about a spin axis, a velocity control system comprising:

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal;

jet means on said vehicle having a thrust component acting substantiallythrough the center of gravity of said vehicle; and

means responsive to said signal and coupled to said jet means foroperating said jet means for applying a force to said vehicle to causesaid vehicle to precess and accelerate said vehicle substantiallytransverse to said axis of spin.

34. In a vehicle capable of traveling in free space while rotating abouta spin axis, an orientation control system comprising:

detector means carried by the vehicle and responsive to electromagneticradiation for generating an electrical signal indicative of the bearingof the source of said electromagnetic radiation relative to an axis ofthe vehicle;

means carried by said vehicle for applying an intermittent torque tosaid vehicle about an axis different from said spin axis; and

means responsive to said signal and coupled to said torque applyingmeans for causing said vehicle to precess so as to reorient said spinaxis with respect to said source.

35. In a vehicle capable of traveling in free space and adapted to bespin stabilized about a spin axis, a velocity control system comprising:

detector means carried by the vehicle and responsive to electromagneticradiation for generating an electrical signal indicative of the bearingof the source of said electromagnetic radiation relative to an axis ofthe vehicle;

means responsive to said signal for applying an intermittent force tosaid vehicle to cause said vehicle to precess and accelerate saidvehicle substantially transverse to said axis of spin; and

nutation damper means carried by said vehicle for damping n-utationalmovement. 36. In combination, a spin stabilized vehicle, means carriedby said vehicle and responsive to energy emitted from an energy emittingsource for generating a signal having a frequency which is a function ofthe spin rate of said vehicle when spinning; and

means responsive to said signal for applying an intermittent torque tosaid vehicle about an axis different from said spin axis to cause saidvehicle to precess so as to move said spin axis to approach alignment toa predetermined orientation with respect to said source.

37. In combination, a spin stabilized vehicle,

means carried by said vehicle and responsive to energy emitted from anenergy entitling source for generating a signal having a frequency equalto the spin rate of said vehicle when spinning; and means responsive tosaid signal for applying an intermittent torque to said vehicle about anaxis difierent from said spin axis to cause said vehicle to precess soas to move said spin axis to approach alignment to a predeterminedorientation with respect to said source. 38. In combination, a vehiclecapable of traveling in free space and adapted to be spin stabilizedabout a spin axis,

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal having a frequency whichis a function of the spin rate of said vehicle when spinning; and

means responsive to said signal for applying an intermittent force tosaid vehicle to cause said vehicle to precess and accelerate saidvehicle transverse to said axis.

39. In combination, a vehicle capable of traveling in free space andadapted to be spin stabilized about a spin axis,

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal having a frequency equalto the spin rate of said vehicle when spinning; and

means responsive to said signal for applying an intermittent force tosaid vehicle to cause said vehicle to precess and accelerdate saidvehicle transverse to said axis.

40. A spin stabilized vehicle, said vehicle including:

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal having a frequency equalto the spin rate of said vehicle when spinning; and

means responsive to said signal for applying an intermittent torque, tosaid vehicle about an axis different from said spin axis, at a ratewhich is equal to the f equency of said signal, with said intermittenttorque causing said vehicle to precess so as to move said spin axis toapproach alignment to a predetermined orientation with respect to saidsource.

41. In combination, a vehicle capable of traveling in free space andadapted to be spin stabilized about a spin axis,

means carried by said vehicle and responsive to energy emitted from anenergy emitting source for generating a signal having a frequency equalto the spin rate of said vehicle when spinning; and

means responsive to said signal for applying an intermittent force tosaid vehicle at a rate which is equal to said frequency of said signalto cause said vehicle to precess and accelerate said vehicle transverseto said axis of spin.

42. A vehicle capable of traveling in free space and adapted to be spinstabilized about a spin axis, said vehicle including:

means for generating a signal having a frequency proportional to thespin frequency of said vehicle;

means on said vehicle for applying torque to said vehicle;

means responsive to said signal and coupled to said torque applyingmeans to cause said vehicle to precess so as to reorient said spin axisin a predetermined direction; and

nutation damper means carried by said vehicle for dumping nutationalmovement.

43. In combination,

a spin stabilized body, means carried by said body for generating asignal having a frequency proportional to the spin frequency of saidbody;

means disposed within said body for supplying fluid under pressure;

at least one controllable valve connected to said means for supplyingfluid under pressure;

at least one jet-forming means connected to said valve;

and control means coupled to said valve for actuating said valve inpulses synchronized with the spin of said body.

44. In combination,

a spin stabilized body, means carried by said body for generating asignal having a frequency proportional to the spin frequency of saidbody;

fluid supply means associated with said body;

a controllable valve connected to said fluid supply means;

fluid expulsion means coupled with said valve and oriented to expel saidfluid along a line displaced from a line passage through the center ofgravity of said body;

and control means coupled to said valve for controlling said valve inpulses synchronized with the spin of said body.

45. In combination,

a spin stabilized body, means carried by said body for generating asignal having a frequency proportional to the spin frequency of saidbody;

fluid supply means associated with said body;

a controllable valve connected to said fluid supply means;

fluid expulsion means coupled with said valve and oriented to expel saidfluid substantially along a line normal to said axis;

and control means coupled to said valve for controlling said valve inpulses synchronized with the spin of said body.

46. In combination,

a spin stabilized body, means carried by said body for generating asignal having a frequency proportional to spin frequency of said body;

and means associated with said body for expelling fluid more than oncefrom a particular location thereon to exert a series of incrementalforces on said body during several revolutions of said body about saidaxis, said means controlling the duration of each expulsion of fluid tobe short compared to the time of one revolution of said body about saidaxis, said means controlling the time of occurrence of each expulsion offluid to be at a predetermined part of the cycle of revolution of saidbody about said said axis, whereby said series of incremental forcesprovide a net force on said body in a predetermined direction.

47. In combination,

a spin stabilized body, means carried by said body for generating asignal having a frequency proportional to spin frequency of said body;

fluid supply means associated with said body, a controllable valveconnected to said fluid supply means;

fluid expulsion means coupled with said valve for expelling said fluidfrom said body in a fixed direction with respect to said body;

and control means coupled to said valve for actuating said valve morethan once to appl a series of incremental forces to said body duringseveral revolutions of said body about said axis, said control meanscontrolling the duration of each actuation of said valve to be shortcompared to the time of one revolution of said body about said axis,said control means controlling the time of occurrence of each actuationof said valve to be at a predetermined part of the cycle of revolutionof said body about said axis, whereby said series of incremental forcesprovide a net force on said body in a predetermined direction.

48. In combination,

a spin stabilized body;

means carried by said body for generating a signal having a frequencyproportional to the spin frequency of said body;

and means responsive to said signal for applying a torque to said bodyto precess the spin axis of said body through a desired sequence oforientation.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS 2,852,208 9/1958 Schlesman 244-14 2,856,14210/1958 Haviland 244--14 2,857,122 10/1958 Maguire 244-14 2,911,16711/1959 Null 244-14 3,028,119 4/1962 Coble 24414 3,072,365 1/1963Linscott et a1. 24414 2,415,348 2/1947 Haigney 2443.l6 2,421,085 5/1947Rylsky 244-3. 16 X 2,943,822 7/1960 Hamilton 244-3.22 X 3,000,307 9/1961Trotter 2443.16 2,492,057 12/1949 Noxon 745.43 2,772,570 12/1956 Judson745.43 2,795,956 6/1957 McNatt 745.4 2,780,104 2/1957 Carlson et a174-5.43 2,935,942 5/1960 De Young et al. 2443.16 X 2,948,813 8/1960Osborne 250-203 VERLIN R. PENDEGRASS, Primary Examiner US. Cl. X.R.244-322 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION ReissueNo. 26,887 May 19, 1970 William B. McLean It is certified that errorappears in the above identified patent and that said Letters Patent arehereby corrected as shown below:

Column 9, line 55, "in" should read on Column 10, line 55, "vehicleshould read vehicle Column 12, line 59, accelerdate" should readaccelerate Column 13, line 44, "passage" should read passing Column 14,line 9,

cancel "said", first occurrence.

Signed and sealed this 23rd day of February 1971 (SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Attcsting Officer Commissioner of Patents

